THE LIFT INVARIANT DISTINGUISHES COMPONENTS OF HURWITZ SPACES FOR A5.

Hurwitz spaces are moduli spaces of curve covers. The isomorphism classes of covers of P¹ℂ with given ramification data are parameterized combinatorially by Nielsen tuples in the monodromy group G. The Artin braid group acts on Nielsen tuples, and the orbits of this action correspond to the connected components of the corresponding Hurwitz space. In this article we consider the case G = A5. We give a complete classification of the braid orbits for all ramification types, showing that the components are always distinguishable by the Fried-Serre lift invariant. [ABSTRACT FROM AUTHOR]